The critical need remains to improve our ability to prevent breast cancer. An area of research that holds great promise for reducing breast cancer risk concerns improving our knowledge of the impact of environmental factors, especially when these factors appear to act when the breast is particularly susceptible to changes that ultimately lead to cancer. The proposed Coordinating Center for the Breast Cancer and the Environment Research Program (BCERP) consortium will support research that follows national recommendations to prioritize prevention, use transdisciplinary research approaches, and intensify the study of chemical and physical factors that potentially influence the risk of developing breast cancer. Our overarching goal is to support integrated scientific research to enhance our understanding of environmental and genetic factors underlying breast cancer risk throughout the lifespan, with particular focus on windows of susceptibility. Specific Aims are: 1- to provide leadership in team science by identifying opportunities to facilitate cross- project transdisciplinary interaction, standardize and integrate research efforts, and maximize use of resources; 2- to provide exceptional coordination for the consortium including defining a shared vision and mission, identifying shared resources, developing standard policies, managing Opportunity Funds to distribute to Consortium members, assisting NIH staff, and supporting a Steering Committee, Working Groups, and an annual scientific meeting; 3- to leverage sharing of data and other resources among BCERP members; 4- to support cross-project communication as well as dissemination of findings to diverse partners and audiences including the broader breast cancer and environmental science research communities, and to support the training and mentoring of the next generation of breast cancer researchers; and 5- to facilitate internal and external evaluation to maximize the Coordinating Center's and Consortium's performance, transdisciplinary nature, productivity and effectiveness. Our mission is to provide intellectual leadership and logistical support for the BCERP consortium by identifying and facilitating opportunities for cross-BCERP collaboration, and disseminating research findings through partnerships with stakeholders. Our multidisciplinary team includes experts in breast cancer epidemiology, basic science, environmental health, toxicology, program evaluation, biostatistics, outreach/community engagement, and research administration, as well as mentoring and training. The University of Wisconsin Carbone Cancer Center provides the ideal environment for supporting the Coordinating Center due to its multiple resources and strong established relationships with local, regional, and national research and advocacy organizations. The BCERP Coordinating Center will use multiple innovative approaches to leverage Consortium members' common passion for elucidating the role of environmental factors that act during windows of susceptibility to increase risk of breast cancer, provide opportunities for collaboration, and enable BCERP to bring about substantive reductions in the burden of this common disease.